Orifice Restrictors are the simplest method of flow control and are one of Air Logic's best-selling product lines. Also called Precision Orifices or Flow Restrictors, they work on the principle of flow restriction by orifice diameter. The size is identified in the part number and by color codes assigned to each specific dimension. In addition to orifice diameter, Air Logic controls many smaller factors that have an impact on the total restriction of the orifice.